On January 1, 2017, we acquired a 70% interest in a seventeen-clinic physical therapy practice. The purchase price for the 70% interest was $10.7 million in cash and $0.5 million in a seller note that is payable in two principal installments totaling $250,000 each, plus accrued interest. The first installment was paid in January 2018 and the second installment is due in January 2019.
In March 2017, we acquired a 55% interest in a company which is a leading provider of workforce performance solutions. Services provided include onsite injury prevention and rehabilitation, performance optimization and ergonomic assessments. The majority of these services are contracted with and paid for directly by employers including a number of Fortune 500 companies. Other clients include large insurers and their contractors. The purchase price for the 55% interest was $6.2 million in cash and $0.4 million in a seller note that is payable, principal plus accrued interest, in September 2018.
On May 31, 2017, we acquired a 70% interest in a four-clinic physical therapy practice. The purchase price for the 70% interest was $2.3 million in cash and $250,000 in a seller note that is payable in two principal installments totaling $125,000 each, plus accrued interest, in May 2018 and 2019.
On June 30, 2017, we acquired a 60% interest in a nine-clinic physical therapy practice. The purchase price for the 60% interest was $15.8 million in cash and $0.5 million in a seller note that is payable in two principal installments totaling $250,000 each, plus accrued interest, in June 2018 and 2019.
On October 31, 2017, we acquired a 70% interest in a nine-clinic physical therapy practice and two management contracts with third party providers. The purchase price for the 70% interest was $4.0 million in cash and $0.5 million in a seller note that is payable in two principal installments totaling $250,000 each, plus accrued interest, in October 2018 and 2019.
On November 30, 2016, we acquired a 60% interest in a 12 clinic physical therapy practice. The purchase price for the 60% interest was $11.0 million in cash and $0.5 million in a seller note that is payable in two principal installments of $250,000 each, plus accrued interest, one of which was paid in November 2017 and one of which is due in November 2018. On February 29, 2016, we acquired a 55% interest in an eight-clinic physical therapy practice. The purchase price for the 55% interest was $13.2 million in cash and $0.5 million in a seller note that was payable in two principal installments totaling $250,000 each, plus accrued interest. The first installment was paid in February 2017 and the next installment was paid in February 2018.
On December 31, 2015, we acquired a 59% interest in a four-clinic practice for $4.6 million in cash and $400,000 in seller notes that were payable in two principal installments of an aggregate of $200,000 each, plus accrued interest. The first installment was paid in December 2016 and the next installment was paid in December 2017. On June 30, 2015, we acquired a 70% interest in a four-clinic physical therapy practice. The purchase price was $3.6 million in cash and $0.7 million in seller notes that are payable plus accrued interest, in June 2018. On April 30, 2015, we acquired a 70% interest in a three-clinic physical therapy practice. The purchase price was $4.7 million in cash and $150,000 in a seller note that was payable in two principal installments of $75,000 each, plus accrued interest. The first installment was paid in April 2016 and the next installment was paid in April 2017. On January 31, 2015, we acquired a 60% interest in a nine-clinic physical therapy practice. The purchase price for the 60% interest was $6.7 million in cash and $0.5 million in a seller note that is payable in two principal installments of $250,000 each, plus accrued interest. The installments were paid in January 2016 and 2017. In addition to the multi-clinic acquisitions, on August 31, 2015, we acquired a 60% interest in a single physical therapy clinic for $150,000 in cash and $50,000 in a seller note that was paid plus accrued interest in August 2016.
Historically, we have generated sufficient cash from operations to fund our development activities and to cover operational needs. We plan to continue developing new clinics and making additional acquisitions in selected markets. We have from time to time purchased the non-controlling interests of limited partners in our Clinic Partnerships. We may purchase additional non-controlling interests in the future. Generally, any acquisition or purchase of non-controlling interests is expected to be accomplished using a combination of cash and financing. Any large acquisition would likely require financing.
We make reasonable and appropriate efforts to collect accounts receivable, including applicable deductible and co-payment amounts. Claims are submitted to payors daily, weekly or monthly in accordance with our policy or payors requirements. When possible, we submit our claims electronically. The collection process is time consuming and typically involves the submission of claims to multiple payors whose payment of claims may be